1. Field of the invention:
The present invention relates to a percutaneous administration type pharmaceutical preparation in tape form containing isosorbide dinitrate (ISDN) as an active ingredient therein.
2. Description of the prior art:
Isosorbide dinitrate (ISDN) and nitroglycerin (NG) are known as an effective medicine for angina pectoris. However, neither of these are effective over a prolonged period of application nor are they effective in suppressing or preventing attacks of angina pectoris after an initial period of effectiveness. Therefore, a pharmaceutical preparation which would supply ISDN gradually and at a constant rate over a long period of time has been desired.
In order to overcome these deficiencies, a percutaneous absorption type pharmaceutical preparation in tape form containing ISDN or pentaerythritol tetranitrate (PETN) has been proposed in U.S. Pat. No. 4,420,470 wherein the adhesive base material is composed of a copolymer containing alkyl acrylate or methacrylate in a concentration of at least 50% by weight, a functional monomer in a concentration of up to 20% by weight and a vinyl ester monomer in a concentration of up to 40% by weight. Such a percutaneous absorption type pharmaceutical preparation in tape form has the following three critical drawbacks:
First, since such a pharmaceutical preparation is administered via the skin kaving a tissue which serves to prevent foreign substances from entering into the body, it is difficult to administer the amount of active ingredients which is sufficient to take a pharmaceutical effect immediately. Thus, a large-sized tape must be applied to the skin and/or an absorption promoter must be incorporated into the adhesive base material.
Second, this pharmaceutical preparation necessarily has a side effect. Due to contact of the adhesive base layer with the skin over a given period of time, the normal secretion, metabolism, expansion and contruction of the skin are prevented and the skin suffers irritation at the edge partion of the tape and/or from the adhesive base layer thereof, resulting in a number of red spots, and in extreme cases, incrustations and/or edemata, on the skin, which can remain for a several days.
Third, a part of the adhesive base material unavoidably remains on the skin when the tape is peeled off.
Additionally, a part of the active ingredients contained in the adhesive base material penetrates through the backing, and/or crystalizes at the interface of the adhesive base layer and the backing, thereby resulting in reduced pharmaceutical effect.